Tennis players planning to participate in the Australian Open should get vaccinated against COVID-19 to avoid any potential bans from entry to the tennis tournament, an official has said.

The state of Victoria, where the Australian Open will be held in Melbourne, has introduced a vaccine mandate for all professional athletes but the authorities have yet to clarify whether overseas athletes or other Australian states must also get vaccinated.

Victoria sports minister Martin Pakula urged players to leave no room for doubt.

"If I was an ATP or WTA player, I'd be getting vaccinated," Pakula told local radio station SEN.

"That will give them the best opportunity to play in the Australian Open with the more minimal restrictions that might be in place for those people."

Both the women's WTA and men's ATP tours have urged players to get vaccinated but some have expressed reservations, including Australian Open men's champion Novak Djokovic, who is opposed to vaccine mandates.

Tennis Australia, which organizes the Grand Slam, has not disclosed any arrangements for players for the upcoming tournament in January.

But fully vaccinated players are expected to enjoy more freedoms to move around and may be able to avoid the country's mandatory 14-day quarantine upon arrival.

Australia's borders remain effectively shut to nonresidents, and Pakula said he did not know whether unvaccinated people would be allowed to enter the country by the time the Australian Open starts on Jan. 17.

"That's going to be the subject, I suspect, of discussion at national cabinet and among the federal cabinet," he said.

"As for the rules that might apply around the Australian Open, specifically, we're in discussions with Tennis Australia and the department of health."

Melbourne has been locked down for months as authorities battle to control an outbreak of the highly infectious delta variant while rolling out vaccinations.

Victoria will lift some lockdown restrictions when 70% of adults are fully vaccinated, which should be late October according to official projections.